Felt and process of making the same



Patented Mar. 10, 1925.

UNITED STATES PATENT OFFICE.

ALBERT L. CLAPP, OF DANVEBS, MASSACHUSETTS FELT AND PROCESS OF MAKINGTHE SAME.

No Drawing. Application filed May 10v To all 20710! if 1/14/ corny/n Beit known that I, ALBERT L. Curr, a itizen of the United States, residingat Danvers, in the county of Essex and State of h'fasswlmst-tts, haveinvented new and useful Improvements in Felt and Processes f Making theSallie of which the f llowing is a specification.

This invention has for its object to pl duce a compressible resilientfelt, capable of use in the manufacture of gun wads insulation forrailway cars, ice houses refrigerators and the like. and which iswater-resistant and which moreover may be produ ed on a paper-malringmachine such as a wet machine so-called.

I first start with a cellulosic material. referably cotton lintersso-called.but in ion of cotton linters I may use jute, rags or othersuitable material. I load a beating engine with approximately 600 poundsof the cellulosic material, e. cotton linters; and, adjusting the rollto t e bed plate beat the raw material with suficient water to ensurefree circulation until the raw material is well beaten without materialhydration. This takes ordinarily in the neighl orho d of 4 hours more orless and effects a disintegration of the fibers. To the contents of theeater tub are added about 50 pounds of rosin size and the beating iscontinued until the rosin size is thoroughly incorporated in the massusually for about 1 hour. Then I add preferably aluminum sulphate inexcess of that needed to precipitate the rosin size in the form ofaluminum resinate. Ordinarily it would take about 25 pounds f alum topreci itate 5 pounds of rosin size. but preferab y I add about 50 poundsof alum, thus providing an excess of .25 pounds. The beating: iscontinued for about 1 hour until the aluminum resinate is recipitated onthe fibers of the mass. The water roll is then raised and about 600pounds of cattle or goat hair (dry weight) derived from tanneries isadded to the beater. Th adjustment of the roll is such that. when thebeater is again started in operation. the contents of the tub arethoroughly intermixed and the hair is brushed without cutting or hardbeating. This may continue for about 1 hour. Wet hair from the tannerymay be used or hair after it has been dried. In any event, such hair hasusually mixed therewith more or less lime. (It is for this reason that Iemploy an excess of alum in the first sizing 1922. Serial No. 559,960.

of the mass. the excess alum serving to neutralize the lime and formsoluble salts which wash ut with tile water.) The mass is then againsized bv the additi n f rosin size and sutlicient alum to reacttherewith for the precipitation of aluminum resinate. For this purpose.I may add for example 30 pounds of rosin size and 10 pounds of alum. thelatter f course being added after th rosin size has been thorcuighlvintermixed with the mass. The amounts f rosin size added at thesedifferent times to the mass of course may be variedv After the beatingand brushing operaticuis. the stock is then she ted n a wet machineuntil the mat rial on the make-up roll is of the desired thickness orcaliper. The material is then stripped from the roll andis dried fiat,after which it may be passed through calender rolls to compact the sh etslightly and to finish the surface of the sheet.

With not so gum] results. inst ad of (lOllle sizin; operation durin; thebeating of the stoclt. the hair may be added to the beater after thetellulosi material has been properly beaten and the rosin size addedafter the hair has been thoroughly intermixed with the cellulosicmaterial during the brushing operation. Even in such case. ecause of thepresence of lime in the cattle or goat hair. I use alum in excess ofthat necessary to react with the rosin size. In su h case after thecotton linters have been beaten for, say. 4 hours with hard beating. ther lls may be lift d and an equal amount f hair added. The beater is thenset in operation and the mass is circulated and intermixed withoutcutting th hair for about 1 hour I may then add 50 pounds of rosin sizeand c ntinue the brushing operation for 1 hour. after which pounds ofalum may b added and the beater continued in operation for another hour.Prefera ly. when the alum is added. the roll is still further lifted toeflect m rely the circulation and intermixing of the components of themass without an actual beating or brushing operation. since the finaloperation of the beater is merely to secure a thorough intermixing ofall of the components of the stock. The pulp is th n sheeted as previusly described.

In some instances instead of using cotton linters or jute r rags, I maysubstitute for all or a portion thereof such cellulosic material aschemical wood pulp -or waste manila, rag or mixed papers,-or sulphite,sulphate or ground Wood screenings,this depending upon the particularuse to which the felt is to be subjected.

The final product is water-resistant, resilient and slow burning. Whenout into blanks of the proper size, it may be used for the manufactureof dust guards, such as employed in railway car journals; or, aspreviously stated, it is excellent as a non-con- (luctor of heat andlends itself to use as an insulation for ice houses, railway cars,refrigerators, etc.

When cotton or other equivalent fiber is used as the initial or startingmaterial, it must be beaten to the required degree of fineness, asotherwise, on the addition of the hair which is only brushed, a stockwould be produced which would be too free and more or less lumpy andwould not properly form or felt on the cylinder mold.

What I claim is:-

1. A soft compressible and resilient waterresistant felt comprising hairand cellulosic material in substantially equal parts in interfeltedrelation and containin a waterproofing precipitate, said materlal havingthe charactertistics of one formed on a paper-making machine.

2. A method of producing a soft compressible water-resistant resilientfelt which comprises beating a cellulosic material, adding andintermixing therewith an approximately equal amount of tanners hairwithout materiall cutting the hair, adding rosin size and eient alum toprecipitate the rosin size and to neutralize lime contained in the hair,and felting and sheeting the stock on a paper machine.

3. The herein described method of producin a water-resistant resilientcom ressible felt, which comprises beating cotton linters'to disinterate the fibers, then adding rosin size an alum in excess of thatrequired to recipitate sodium resinate from the size, adding andintermixing waste tanners hair with the stock without materially cuttinthe hair, the excess alum serving to neutra ize the lime contained inthe hair, then adding rosin size to the mass and precipitating aluminumresinate therefrom by the addition of alum, and finally felting andsheeting the stock on a aper machine 4. A method of pro ucing awater-resistant fibrous material, which comprises beating a cellulosicmaterial to effect a disintegration thereof, precipitating a size on theisintegrated fibers, adding and mixing waste tanners hair with the massto produce a substantially homogeneous mixture, precipitatin a sizethroughout the mass, and finally s eeting the mass on a paper machine.

In testimony whereof I have afiixed my signature.

ALBERT L. CLAPP.

